Human Physiology Dr. Phillip Stepp

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Human PhysiologyDr. Phillip Stepp

• Jan 20th, 2010
• 20 Trustee Science Center
• 1000-1100 AM M/W/F

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• Human Physiology (BIOL 206) Spring 2010
• Dr. Phillip Stepp
• Office 102 Trustee Science Center
• Email pstepp_at_drury.edu or pwsneuro_at_yahoo.com
• Text Human Physiology by Fox, 9th Edition
• Course Description This course is designed to
  give students an in-depth understanding of the
  various physiological systems in humans. Through
  a combination of labs and lectures, students will
  gain an appreciation for the manner in which the
  body coordinates and executes physiological
  functions. Students will also develop an
  appreciation for the complexity of the human body
  and the organization required for the proper
  homeostatic balance the body must maintain in
  order for life to continue. Throughout the
  semester, students will consider anatomy,
  physiology, and biochemistry, of the body and the
  interaction of the various organ systems of the
  human body.

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• Policies (read carefully)
• A. Students will be expected to be on-time for
  each lecture and lab and to remain in class until
  dismissed. Late arrivals and early departures
  will need to be discussed since they tend to
  disrupt the class.
• B. Attendance is expected for all lectures and
  labs. When absent, every student is responsible
  for obtaining class notes and homework
  assignments from other students in the class.
  Therefore, you need to develop responsible
  student contacts. By stating this in the
  syllabus, you are now aware that no late homework
  assignments will be accepted. If an assignment
  is due and you know that you will not be in
  class, have another student hand it in for you.
  All absences will be recorded and any student
  with three or more absences, for any reason, will
  be reported to the Academic Dean and the
  Registrars Office and strongly encouraged to
  drop the course.
• C. Exams may only be made up with prior
  notification or if an emergency situation arises.
  All make-up exams will be given at the end of
  the semester.

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• D. All exams will be individual efforts without
  notes or open books. All electronic devices
  (computers, cell phones, calculators, etc.) will
  be turned off and stored away (and out of sight).
  Homework assignments need to be started early
  enough in order to avoid waiting until the last
  minute and handing in a poor quality assignment.
  Homework assignments can be worked on together.
  In fact, I encourage students to discuss the
  information in the homework assignments to better
  understand the material. HOWEVER, simply copying
  any homework in attempt to complete it on-time
  will be considered academic dishonesty. Also,
  providing your homework so that another student
  may simply copy your answers will also be
  considered academic dishonesty. Any academic
  dishonesty will be dealt with seriously involving
  the notification of the Academic Dean. This
  could result in course failure and/or dismissal
  from the program.
• E. IMPORTANT NOTE ALL FOOD AND DRINKS ARE
  STRICTLY PROHIBITED FROM THE LAB ROOMS AT ALL
  TIMES. THIS WILL BE STRICTLY ENFORCED.
• F. All cell phones need to be turned off
  during lectures and talking during lectures will
  not be tolerated and students may be requested to
  leave. An increasing number of complaints by
  students over the past few semesters has prompted
  this statement.

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• Grading System Final grades will be determined
  as follows
• Five lab assignments 30 pts. each 150 pts.
• Five lecture exams 100 pts. each 500 pts.
• Class Participation 50 pts.
• Total 700 pts.
•  
• A 630 700 pts. (90) C 490 559 pts.
  (70-79)
• B 560 - 629 pts. (80-89)D 420 489 pts.
  (60-69)
• The quizzes and exams are designed to provide
  students with an opportunity to think critically
  and not simply to memorize information. Labs are
  designed to provide hands-on experiences and to
  promote collaborative learning.

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Human Physiology Tentative Schedule (Spring
2010) Week of Lecture/Lab   1/20 Intro
to Physiology (Ch 1, 2, 3) Chemical
Composition of the Body, Cellular Structure
1/25 Intro to Physiology II (Ch 4, 5,
6) Cellular Metabolism Interactions   2/1 C
h 7- Neurons and Synapses   2/8 Ch 8- The
Central Nervous System Crayfish Nerve Lesion
Lab   2/15 Ch 9- The Autonomic Nervous
System 2/22 Lecture Exam 1 Ch 10-
Sensory Physiology   3/1 Ch 12- Muscle
Mechanisms of Contraction and Neural
Control Sensory Physiology Lab   3/8 Ch 12-
Muscle Mechanisms of Contraction and Neural
Control Fatal Vision go-cart driving
PIZZA!!!! Lecture Exam 2  
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3/15 Ch 13- Heart and Circulation Human
ECG/Diving Response Lab   3/22 SPRING
BREAK!!!   3/29 Ch 14- Cardiac Output, Blood
Flow, and Blood Pressure Ch 15- Immune
System   4/5 Lecture Exam 3 Ch 16-
Respiratory Physiology   4/12 Ch 17- Physiology
of the Kidney Respiration Kidney
Lab   4/19 Ch 18- Digestive System   4/26 L
ecture Exam 4 Ch 11- Endocrine Glands
Secretion and Action of Hormones 5/3 Ch 19-
Regulation of Metabolism Goldfish Metabolism
Lab Ch 20- Reproduction   Finals Week
(5/10) Lecture Exam 5
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Human Physiology Introduction- Part I
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Human Physiology

• Physiology the study of nature
• More specifically the study of how things
  function
• French physiologist Claude Bernard is the father
  of modern physiology
• Stated that the internal environment stays
  relatively constant despite external conditions
• Known as homeostasis- the maintainence of
  internal physiological conditions

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Homeostatic Mechanisms

• Homeostasis maintained my neg feedback loops
• Body has a set point for many physiological
  conditions
• Integrating centers monitor information from
  sensors, and make corrections and adjustments
• Integrating centers act on effectors to increase
  or decrease the activity of a particular system-
  usually a muscle or gland
• A Negative feedback loop is a system that
  corrects for deviation from the set point by
  moving the system in a negative (or reverse)
  direction than the current conditions

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Homeostatic Mechanisms

• Example- sweating/shivering
• Normal body temp is about 37 C
• If body temp increases ????
• If body temp decreases ????
• Some rare cases have positive feedback- action of
  effectors amplifies the changes that stimulated
  the effectors
• Example- blood clotting

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Atoms, Ions Chemical Bonds

• Atom- smallest unit of chemical element
• Has protons (), neutrons in nucleus, electrons
  (-) in orbitals
• protonselectrons
• Molecules are formed by sharing of electrons-
  form chemical bonds
• of bonds determined by of electrons it takes
  to complete outermost shell
• Hydrogen can take one, carbon can take 4

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Covalent Bonds

• Covalent bonds formed when identical atoms share
  valence electrons- electrons are equally shared
  (ex- H2 or O2)
• Since e- are equally shared, they are nonpolar
• Covalent bonds with different atoms are polar-
  more e- might be pulled to one side of the
  molecule than the other (ex- H20)

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Ionic Bonds

• Ionic bonds result when 1 valence e- from one
  atom are transferred to a 2nd atom- no sharing
• First atom loses e-, so it becomes charged ion
  (anion)
• Second atom gains e-, so it becomes negatively
  charged ion (cation)
• NaCl is an example- in water, dissociated into
  Na and Cl-

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Ionic Bonds

• Ionic bonds are weaker than covalent polar bonds,
  and dissociate easily in water
• Na and Cl- attract H20 molecules, and the H20 in
  turn attract other molecules, forming hydration
  spheres around each ion
• This is what makes a molecule soluable in
  water
• Hydrophilic molecules form hydration spheres
  around themselves due to charge differences (ex
  glucose)
• Hydrophobic molecules have nonpolar covalent
  bonds and do not form hydration spheres-
  insoluble in water

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Hydrogen Bonds

• When H forms a polar covalent bond with O or N,
  the H gains a charge due to the e- being toward
  the other atom
• Since H now has a slight charge, it has weak
  attraction for another electronegative atom (O or
  N) that is near it- this is a hydrogen bond
• H bonds are weak, but important because they are
  involved for folding and 3D shapes of large
  organic molecules (proteins, DNA)
• Also H bonds can form between H20 molecules-
  important in creating surface tension in water
  and lungs

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Acids, Bases, and pH Scale

• Some water molecules ionize to form H (proton)
  and OH- (hydroxyl ion)
• Solution with 10-7 molar concentration of H and
  OH- is considered neutral (pH 7)
• Solution with higher H is acidic- can release
  H protons into solution (pH 0-7)
• Solution with lower H is basic- it removes H
  from solution (pH 7-14)

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Carbohydrates

• Carbohydrates contain contain carbon, hydrogen,
  and oxygen in a certain proportion
• CnH2nOn
• Monosaccharide- simple sugars
• C6H12O6 can be for Glucose, Galactose, or
  Fructose, depending on atom arrangement
• Disaccharide- two mono- joined by covalent bond
  to make a double sugar (ex sucrose)
• Polysaccharide- numerous mono- joined together
  (ex glycogen)

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Lipids

• Have varying chemical structure, but are all
  insoluble in water
• Because they are mostly hydrocarbon chains and
  rings which are nonpolar and hydrophobic
• Triglycerides- includes fat and oil, formed by
  condensation of one glycerol with three fatty
  acids
• Saturated- C in chain are joined by single
  covalent bond so each C can also be bound to 2 H
  atoms
• Unsaturated- C in chain are joined by some double
  covalent bonds, and not all C have 2 H
• Steroids are also considered lipids- derived from
  cholesterol, and important for production of sex
  steroids (estrogen, progesterone, testosterone)
  and corticosteroids (hydrocortisone and
  aldosterone)

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Formation of Triglycerides
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Lipids- Phospholipids

• Lipid molecules that contain a phosphate group
• Have a polar end (phosphate group) that is
  hydrophilic
• Have a nonpolar end (fatty acid molecules) that
  are hydrophobic
• In water, plipids form micelles- hollow bubbles
  of plipds with hydrophilic heads towards H20, and
  tails away from H20
• Very important in forming the cell membrane, as
  well as decreasing H20 surface tension

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Phospholipid Structure
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Proteins

• Proteins are composed of amino acids (AA)-
  compound with an amino group (NH2) on one end,
  and a carboxyl group (COOH) on the other
• There are 20 different amino acids
• AA can be joined together by peptide bonds to
  form peptides or polypeptides
• If 100 AA are linked, the product is a protein

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Proteins

• Proteins have
• Primary structure- sequence of AA in protein
• Secondary Structure- shape of the protein due to
  H bonds
• Either alpha helix or beta sheet
• Tertiary structure- how the protein bends and
  folds on itself due to interactions among AAs
• Can denature proteins by various means, including
  pH, and heat
• Quaternary structure- how a number of polypeptide
  chains are bound together

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Cell Structure and Cytology

• Human body is composed of 60 trillion to 100
  trillion cells (only 270 to 300 individual
  different types)
• Cells- most basic, independent unit of life (part
  of the Cell Theory)
• Metabolism - sum total of all reactions that
  occur with the body
• catabolic reactions (chemical breakdown) vs.
  anabolic reactions (chemical build-up)
• Cellular Diversity (270 to 300 individual
  different types)
• size range - few micrometers (µm) to approx. 140
  µm (example an RBC is approx. 7.5um in diameter)
• function and structure are closely related
  (important point to remember throughout this
  course)

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• Chemistry of the cell important elements
• carbon, oxygen, hydrogen, nitrogen, phosphorus,
  sulfur, calcium, potassium, sodium, and magnesium
  ( most common in the body at approximately 65)
• In fact Oxygen (65), Carbon (18), Hydrogen
  (10) and Nitrogen (3)
• Water (universal solvent with several other
  properties) and dissolved substances (solute)
• electrolytes compounds that ionize in water
  an carry an electrical charge (acids, bases and
  salts)
• 4 major types of macromolecules proteins,
  carbohydrates, lipids, and nucleic acids with
  building blocks of amino acids, monosaccharides,
  fatty acids and glycerol and nucleotides,
  respectively.

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Plasma Membrane

• cell (plasma) membrane - 6.5 to 10 nm (65 to 100
  A) thick
• phospholipid bilayer (with some cholesterol
  molecules in hydrophobic region)
• hydrophilic (phosphate heads) vs. hydrophobic
  (fatty acid tails) portions of phospholipids
• scattered membrane proteins (peripheral or
  surface and integral or embedded)
• may possess pores (0.7 to 1.0 nm or 7 to 10 A)
  for movement through the membrane
• may be glycosylated, even to point where it forms
  a sugar coating called a glycocalyx
• semipermeable barrier - selective exchange of
  materials across the membrane - passive and
  active processes (see notes below)

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Plasma Membrane

• The six major factors that affect membrane
  transport
• membrane structure the phosholipid bilayer and
  scattered proteins
• size of molecules smaller molecules pass
  through with ease
• ionic charge charged molecules do not pass
  through easily
• lipid solubility steroids and other lipids pass
  through with ease
• carrier molecules the number of embedded
  proteins with pores makes a difference
• pressure differences greater pressures help
  push substances through the membrane

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Plasma Membrane

• Passive (does not use cellular (ATP) energy
• Simple diffusion
• Facilitated diffusion
• Osmosis
• Filtration
• Dialysis (artificial)
• Active (uses ATP (cellular) energy
• Active transport (uses carrier molecules)
• Exocytosis (secretion)
• Endocytosis (uptake and vesicle formation)
• Pinocytosis (uptake of liquids)
• Phagocytosis (uptake of solids)

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Cytoplasm

• Cytoplasm - gel-like substance (colloidal
  suspension) that fills the cell's interior of a
  cell that is
• 80-90 water, filled with metabolites, waste
  materials, building blocks, enzymes, etc.
• suspends the variety of organelles and inorganic
  colloids
• Very important dynamic substance where many
  metabolic chemical reactions take place

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Cellular Organelles

• Organelles - variety of distinct cellular
  components
• some membranous (RER, SER, Golgi complex, etc.)
• some vesicular or granular (lysosomes,
  peroxisomes, melanin, glycogen, etc.)
• some filamentous (microtubules, intermediate
  filaments, microfilaments, etc.)

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Endoplasmic Reticulum

• Endoplasmic reticulum - 2 types (rough ER vs.
  smooth ER)
• membranous sacs or tubules with their interior
  regions referred to as the cisternae
• may attach to the inside of the cell membrane and
  possibly to the nucleus or other organelles
• Rough ER (RER) - with ribosomes attached for
  protein synthesis, primarily secretory proteins
  (pinch off as vesicles) also, RER possesses
  enzymes in the membranous walls that produce some
  lipids
• Smooth ER (SER) - lacks ribosomes also possesses
  enzymes in its walls for lipid synthesis, but
  unlike RER, most of the lipids are steroids also
  contains enzymes that detoxify poisons (alcohol,
  drugs, etc.)

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Ribosomes

• Ribosomes - small particles (12-15 nm in
  diameter) required for protein synthesis each
  ribosome consists of
• Two subunits (60S and 40S), each composed of
  protein and r-RNA.
• May attach to membranes (primarily used to
  produce secretory proteins) or may form
  free-floating structures called polysomes or
  polyribosomes (primarily used to produce
  intracellular proteins).

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Golgi Complex

• Golgi complex - series of slightly curved,
  flattened membranous sacs with vesicles located
  near its expanded ends
• Found near the nucleus and is continuous with the
  (R)ER.
• Packages secretory granules and plays a role in
  lysosome formation.
• Glycosylates proteins (adds CHOs) to form
  glycoproteins and concentrates proteins (by
  removing water) in mature secretory granules.

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Mitochondria

• Mitochondria - double-membraned organelle, found
  to exist in various shapes and numbers.
• The outer membrane is smooth whereas the inner
  membrane is folded to form shelf-like cristae
  to increase the membranes surface area.
• The semisolid substance within the mitochondria
  is called the matrix and is found between
  cristae with ribosomes (w/ 50S and 30S subunits),
  granules that bind to divalent cations (e.g.
  Ca, Mg), and prokaryotic-like DNA and can
  therefore self-duplicate to meet increased energy
  demands.
• They are often referred to as the powerhouse of
  the cell because produces ATP - required for
  metabolic energy. Their presence supports the
  endosymbiotic theory (in plants, chloroplasts do
  too).

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Lysosomes Perixisomes

• Lysosomes - membrane-bound structure that possess
  powerful digestive enzymes that appear granular
  when inactive and vesicular when activeEnzymes
  are capable of digesting proteins, lipids,
  certain carbohydrates, DNA and RNA
• When attached to phagocytic vesicles, lysosomes
  are known as secondary lysosomes - digest to
  provide cell with raw materials for synthetic
  reactions in the cell
• Remaining undigested materials in vacuoles -
  residual body
• May digest parts of the cell they reside in by
  attaching to a vacuole or an intracellular
  component - this is known as autophagocytosis
• Peroxisomes - also known as microbodies and
  resemble lysosomes
• Possess powerful oxidative enzymes used to obtain
  energy from molecules and enzymes that degrade
  H2O2 into H2O and O2 (H2O2 is very toxic to the
  cell) using an enzyme called catalase or
  peroxidase.

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Fibrils and Microtubules

• Fibrils and Microtubules - found coursing
  throughout the cytoplasm making up the
  "cytoskeleton".
• Fibrils, also called microfilaments (6 nm), are
  solid, rod-like structures that may occur in
  bundles. They are composed of proteins,
  especially actin and myosin.
• Microtubules (25 nm) are hollow, tubular rods of
  various lengths and are composed of protein
  subunits called tubulin.
• Microfilaments play a major role in muscle
  contraction.
• Microtubules direct intracellular movement,
  especially the movement of secretory granules, by
  using "MAPS" (microtubule associated proteins) -
  like a conveyer belt.
• A variety of intermediate filaments (10 nm) also
  contribute to the cytoskeleton and cellular
  connections.

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Cilia and Flagella

• Cilia and flagella - basically, the same thing ?
  cytoplasmic extensions of the cell with a core of
  microtubules in the classic "9 2" arrangement.
• The major difference, cilia are short and
  numerous, and flagella are long and few in number
  (usually one).
• Cilia move substances along a cell surface,
  whereas flagella typically move a cell.
• At the base of each cilium or flagellum, is a
  basal body composed of 9 triplets of
  microtubules. They act as movement coordinators
  for each cellular projection.

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Centrosome and Centrioles

• Centrosome and Centrioles - the centrosome is a
  spherical, non-membranous mass near the nucleus
  that contains the paired, rod-shaped centrioles.
  
• Centrioles are composed of 27 microtubules
  arranged in a pinwheel fashion with 9 sets of
  triplets. The pair of centrioles are oriented at
  right angles to each other and play a role in
  mitosis and meiosis (cell division) by directing
  the movement of chromosomes.
• Cells that do not divide (mature muscle and nerve
  cells) lack a centrosome.

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Nucleus, Necleolus, and Chromatin

• Nucleus - large spherical structure encased by a
  double membrane pores (approx. 40 to 45 nm thick)
  called the nuclear envelope with many nuclear
  pores (up to 25 of envelope surface.
• The space in the membrane is called the
  perinuclear cisterna (or space).
• Two important structures within the nucleus are
  the nucleolus and chromatin. They are found
  embedded in the nucleoplasm.
• Nucleolus - small nonmenbranous mass composed of
  protein and RNA
• Functions to produce ribosomal subunits which
  leave the nucleus through nuclear pores to
  function in the cytoplasm.
• Chromatin - coiled, thread-like genetic material
  composed of protein and DNA which functions to
  control synthetic activity of the cell via
  protein (enzyme) synthesis

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Cell Division- Mitosis and Meiosis

• Mitosis - cell division where DNA replicates,
  then divides once - most common type of all
  division
• Meiosis - cell division where DNA replicates,
  then divides twice - only occurs in the testes
  and ovaries

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DNA

• DNA - deoxyribonucleic acid composed of
  nucleotides.
• Each nucleotide has 3 parts phosphate, sugar,
  and nitrogenous base.
• Only the bases differ with 4 different types
  adenine, guanine, cytosine, thymine.
• Complementary base pairing A T and G C.

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RNA

• RNA - composed of nucleotides, like DNA, except
  no thymine. Instead RNA has uracil so A - U
  pairs up
• mRNA - carries the genetic message or "codon" (3
  nucleotides long) produced from a DNA "triplet
  therefore, has a complementary sequence.
• There are 64 possible codon sequences coding for
  only 20 different amino acids you will only
  need to learn four specific codons.
• tRNA - recognizes mRNA codon using a
  complementary "anticodon" and delivers a specific
  amino acid to a growing polypeptide chain.
• rRNA - complexes with proteins to form ribosomes,
  upon which proteins are produced
• important codons AUG start codon and UAA,
  UAG, and UGA stop codons
• example sequence CCG GGA AUG CCU AGU GUG CAG UUG
  UAA GCU RNA for 6 amino acids (start)
  (stop)

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Replication, Transcription and Translation

• Replication DNA makes exact (or nearly exact)
  copy of itself
• Transcription DNA makes RNA (makes all 3 types
  ribosomal RNA, transfer RNA, and messenger RNA)
• Translation protein synthesis (uses all 3 types
  of RNA) and occurs on ribosomes (free or
  membrane-bound)

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